Ok, but there is no need that the boomers stand together directly (magnet to magnet)?
I mean magnet to magnet is equal to magnet-centerbrace-magnet? I just have to stick the boomers to the centerbraces ?

It is very difficult to get the good plywood!! I can get some okoume in 12 mm, but birch is very difficult to find. Number of ply should be 7 minimum no?
It is the last important thing i did not get...

I will post some photo of the tweeter improvment. I just filled the gap around the tweeter but put nothing on the back, you will tell me if i should do more.

Thanks Saturnus to be so helpfull, it impossible to get some answer from 41Hz... But no problem, i got the essential thing from them : the amplifier

Got this today: Komplett.no - Søk: Fiio E12 Mont Blanc
Seems like it does the job for Boominator Signatur.
I like to use same batteries to Power player and AMp, What to use so i dont get groundloop. I cant find any spesific sugestion on that.
Bjoern